First Normal Form (1NF) Last Updated : 25 Jul, 2025 Comments Improve Suggest changes Like Article Like Report First Normal Form (1NF) ensures that the structure of a database table is organized in a way that makes it easier to manage and query. A relation is in first normal form if every attribute in that relation is single-valued attribute or it does not contain any composite or multi-valued attribute. It is the first and essential step in to reduce redundancy, improve data integrity and reducing anomalies in relational database design. A relation (table) is said to be in First Normal Form (1NF) if:All the attributes (columns) contain only atomic (indivisible) values.Each column contains values of a single type.Each record (row) is unique, meaning it can be identified by a primary key.There are no repeating groups or arrays in any row.Rules for First Normal Form (1NF) in DBMSTo follow the First Normal Form (1NF) in a database, these simple rules must be followed:Every Column Should Have Single ValuesEach column in a table must contain only one value in a cell. No cell should hold multiple values. If a cell contains more than one value, the table does not follow 1NF.Example: A table with columns like [Writer 1], [Writer 2], and [Writer 3] for the same book ID is not in 1NF because it repeats the same type of information (writers). Instead, all writers should be listed in separate rows.All Values in a Column Should Be of the Same TypeEach column must store the same type of data. You cannot mix different types of information in the same column.Example: If a column is meant for dates of birth (DOB), you cannot use it to store names. Each type of information should have its own column.Every Column Must Have a Unique NameEach column in the table must have a unique name. This avoids confusion when retrieving, updating, or adding data.Example: If two columns have the same name, the database system may not know which one to use.The Order of Data Doesn’t MatterIn 1NF, the order in which data is stored in a table doesn’t affect how the table works. You can organize the rows in any way without breaking the rules.Example: Consider the below COURSES Relation :In the above table, Courses has a multi-valued attribute, so it is not in 1NF. To make the table in 1NF we have to remove the multivalued attributes from the table as given below:1NFNow the table is in 1NF as there is no multi-valued attribute present in the table. First Normal Form in DBMS Visit Course First Normal Form in DBMS First Normal Form Comment More infoAdvertise with us M mithlesh upadhyay Follow Improve Article Tags : DBMS GATE CS DBMS-Normalization Similar Reads DBMS Tutorial – Learn Database Management System Database Management System (DBMS) is a software used to manage data from a database. A database is a structured collection of data that is stored in an electronic device. 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